Answer: The answer is C.
Explanation: Soil includes 40-45 percent inorganic matter, 5% organic matter, 25% water, and 25% air. The right combination of air, water, minerals, and organic matter is essential for plant life to thrive. Microorganisms (both dead and alive) and decaying plants make up humus, the organic stuff in soil.
A. the plate tectonic theory is the right answer
Many things caused the crash. Taxes were too high, bad bank practices caused a recession, and too many workers went on strike (there were many other causes but thats all o could think of)